As you might well we see many galaxies interacting collideing and coeless into larger galaxy. Our own Milkyway is headed for a head on collion with Andromada in 3 billion years. Looking for habital planets in our own galaxy is a waste of time. Our much smaller milkyway will be ripped apart and stars will be slung out or into the middle of this train wreck. That will continues churning up new stars and old are consumed by the new andromada. We have only 3 billion years to find another earth but outside our own galaxy. So consuming all your time and effort to find habital planets in our own galaxy is a waste. It will take millions of years to travel to another galaxy but we have to start looking at how we can ensure mankind will survive.

considering the gravity involved the a collison is essentially unlikely or almost impossible for solar systems to collide. Look at our own Galaxy. you dont see any evidence of collisions even though the bands collide and recombine galactically often.In a rich man's house there is no place to spit but his face.
Diogenes Of Sinope

I have seen or read that there is evidence that the Milky Way has absorbed several smaller Galaxies in the past. I think also that you will find that the andromeda galaxy is the larger of the two by a big margin. But what does any of this have to do with searching for new planets to populate? Our sun will most likely be history before the Milky Way and Andromeda merge.Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.

I have seen or read that there is evidence that the Milky Way has absorbed several smaller Galaxies in the past. I think also that you will find that the andromeda galaxy is the larger of the two by a big margin. But what does any of this have to do with searching for new planets to populate? Our sun will most likely be history before the Milky Way and Andromeda merge.

. . . M31 may be less massive than our own galaxy, although the error range is still too large to say for certain. Even so, the masses of the Milky Way and M31 are comparable. . .

As I stated in a previous post, the galaxies are roughly the same size with our galaxy probably having a slight edge. I do actually research this stuff before I post it. Others . . not-so-much :PPure mathematics is, in its way, the poetry of logical ideas.

I do too! My sources list Andromeda as having an estimated trillion stars whereas the Milky Way is estimated to have between 100-400 billion stars and their masses are estimated to have about the same proportions. I guess the uncertainty is great enough to cause somewhat different estimates from different sources.

But I stand by my original conclusion that we (humans) don't have anything to worry about from the expected galactic collision and it's impact on our solar system for a very long time and that if we develope the capability for interstellar travel our fate will be in our own hands.Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.

I do too! My sources list Andromeda as having an estimated trillion stars whereas the Milky Way is estimated to have between 100-400 billion stars and their masses are estimated to have about the same proportions. I guess the uncertainty is great enough to cause somewhat different estimates from different sources.

But I stand by my original conclusion that we (humans) don't have anything to worry about from the expected galactic collision and it's impact on our solar system for a very long time and that if we develope the capability for interstellar travel our fate will be in our own hands.

Agreed (on the don't worry about it) idea. The two galaxies are comparable in mass and, when it comes to collisions, mass is everything Agree to disagree on the size estimates. :)Pure mathematics is, in its way, the poetry of logical ideas.

This collision will scatter stars over thousands of light years. It will require a million years to develope enough to achieve interstellar travel. Our sun and planet can change orbits immensely gravity of the largest wins.

I can only imagine the gravitional tug of war with nearby stars slung into new orbits. Then again we might peaceibily merge, but we are in the outskirts of the milkyway and most reasonible to be slung lightyears from where we were. Three billion years sounds so far away but think it will take a million years to travel to another galaxy. Its a roll of the dice do you stay or leave.